Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261, United States.
Center for Nanoscale Multifunctional Materials, Mechanical & Materials Engineering, Wright State University, Dayton, OH 45324, United States.
Acta Biomater. 2016 Mar 1;32:77-88. doi: 10.1016/j.actbio.2016.01.004. Epub 2016 Jan 5.
While several scaffolds have been proposed for skeletal muscle regeneration, multiscale hierarchical scaffolds with the complexity of extracellular matrix (ECM) haven't been engineered successfully. By precise control over nano- and microscale features, comprehensive understanding of the effect of multiple factors on skeletal muscle regeneration can be derived. In this study, we engineered carbon-based scaffolds with hierarchical nano- and microscale architecture with controlled physico-chemical properties. More specifically, we built multiscale hierarchy by growing carbon nanotube (CNT) carpets on two types of scaffolds, namely, interconnected microporous carbon foams and aligned carbon fiber mats. Nanostructured CNT carpets offered fine control over nano-roughness and wettability facilitating myoblast adhesion, growth and differentiation into myocytes. However, microporous foam architecture failed to promote their fusion into multinucleated myotubes. On the other hand, aligned fibrous architecture stimulated formation of multinucleated myotubes. Most importantly, nanostructured CNT carpets interfaced with microscale aligned fibrous architecture significantly enhanced myocyte fusion into multinucleated mature myotubes highlighting synergy between nanoscale surface features and micro-/macroscale aligned fibrous architecture in the process of myogenesis.
Due to limited regenerative potential of skeletal muscle, strategies stimulating regeneration of functional muscles are important. These strategies are aimed at promoting differentiation of progenitor cells (myoblasts) into multinucleated myotubes, a key initial step in functional muscle regeneration. Recent tissue engineering approaches utilize various scaffolds ranging from decellularized matrices to aligned biomaterial scaffolds. Although, majority of them have focused on nano- or microscale organization, a systematic approach to build the multiscale hierarchy into these scaffolds is lacking. Here, we engineered multiscale hierarchy into carbon-based materials and demonstrated that the nanoscale features govern the differentiation of individual myoblasts into myocytes whereas microscale alignment cues orchestrate fusion of multiple myocytes into multinucleated myotubes underlining the importance of multiscale hierarchy in enhancing coordinated tissue regeneration.
虽然已经提出了几种用于骨骼肌再生的支架，但具有细胞外基质（ECM）复杂性的多尺度层次支架尚未成功构建。通过对纳米和微观尺度特征的精确控制，可以深入了解多种因素对骨骼肌再生的影响。在这项研究中，我们通过控制物理化学性质，成功设计了具有纳米和微观层次结构的碳基支架。更具体地说，我们通过在两种支架上生长碳纳米管（CNT）地毯来构建多尺度层次结构，这两种支架分别是相互连接的微孔碳泡沫和定向碳纤维垫。纳米结构的 CNT 地毯可以很好地控制纳米粗糙度和润湿性，从而促进成肌细胞的黏附、生长和分化为肌细胞。然而，微孔泡沫结构不能促进它们融合成多核肌管。另一方面，定向纤维结构刺激了多核肌管的形成。最重要的是，纳米结构的 CNT 地毯与微尺度定向纤维结构界面显著增强了肌细胞融合成多核成熟肌管，突出了纳米级表面特征与微/宏观定向纤维结构在肌发生过程中的协同作用。
由于骨骼肌的再生潜力有限，刺激功能性肌肉再生的策略非常重要。这些策略旨在促进祖细胞（成肌细胞）分化为多核肌管，这是功能性肌肉再生的关键初始步骤。最近的组织工程方法利用了各种支架，从去细胞化基质到定向生物材料支架。尽管大多数方法都集中在纳米或微尺度组织上，但缺乏将多尺度层次结构构建到这些支架中的系统方法。在这里，我们成功地将多尺度层次结构设计到碳基材料中，并证明纳米级特征控制单个成肌细胞分化为肌细胞，而微尺度排列线索协调多个成肌细胞融合成多核肌管，强调了多尺度层次结构在增强协调组织再生方面的重要性。
